The present invention relates to a heat exchanger comprised of individual plates with flow channels that can be used in counterflow and parallel flow operation. The flow channels are formed between two plates combined to form a pair and between adjacent ones of the pairs stacked atop one another to form the heat exchanger. The individual plates and the pairs formed from two plates are connected to one another at longitudinal rim portions extending parallel to the main flow direction. The inlets and the outlets of each flow channel are diagonally arranged in the main flow direction. The inlets and outlets of flow channels for one medium are arranged directly atop one another, while the inlets and outlets of the flow channels for the first medium are staggered relative to the inlets and outlets of the flow channels for the second medium by half the height of the pairs.
Heat exchangers of the aforementioned kind comprised of individual plates and having flow channels to be operated in counterflow are known from German patent 41 00 940. They are of an extremely compact construction, provide a high heat exchange efficiency, and can be produced inexpensively even for aggressive media.
It is an object of the present invention to improve the efficiency of the known heat exchangers, while simultaneously reducing their dimensions.